Question

What does power set mean?

Answer 1

Power Set: 

The collection of all subsets of set A is called the power set of A. It is denoted by P(A). In P(A), every element is a set. 

For example;

If A = {p, q} then all the subsets of A will be 

P(A) = {∅, {p}, {q}, {p, q}} 

Number of elements of P(A) = n[P(A)] = 4 = 22

In general, n[P(A)] = 2m where m is the number of elements in set A.